sedimentary
Agate
Silicon dioxide (chalcedony), SiO2
Hardness of 6.5 to 7 on the Mohs scale, waxy to vitreous luster, cryptocrystalline structure, translucent to opaque with banded or mottled patterns, specific gravity of 2.60 to 2.65.
Identified More sedimentary →
Explore Agate in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness of 6.5 to 7 on the Mohs scale, waxy to vitreous luster, cryptocrystalline structure, translucent to opaque with banded or mottled patterns, specific gravity of 2.60 to 2.65.
Formation & geological history
Formed by the deposition of silica from groundwater in cavities of igneous or sedimentary rocks, typically over millions of years in volcanic regions.
Uses & applications
Used in ornamental objects, jewelry, carvings, and scientific instruments like mortar and pestles due to its durability.
Geological facts
Agate is one of the most popular materials used in art carving and lapidary work. Ancient civilizations used it for talismans and seals.
Field identification & locations
Identified by its waxy luster, conchoidal fracture, and characteristic banding or layered appearance. Found worldwide, particularly in Brazil, Uruguay, India, and parts of the United States like Oregon.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Banded Siltstone / Mudstone Pebble
Siltstone / Argillite
sedimentary